Yes, it could be. There are a lot that color. Madame Julia is not true red though most pics I find are redder than yours. The shape of the stamens is the same and she has a white reverse too.

It could be :-) But if it came with a tag labeling it as Mme Julia Correvon, it quite likely is. I find it very difficult to ID clematis only based on flower color, size or number of tepals - IME, all can vary quite widely, especially the color. Depending on the maturity of the vine, its exposure to sunlight or shade and even the age of the individual flowers, the color can be off from the described. Red and blues seem to produce the greatest variance, ranging from purple to magenta to an almost scarlet for the reds and all shades of lilac. lavender and purple for the blues.